Questions to an astronaut

What would you ask an astronaut if you had the chance? Young kids already know: “do you miss your mom?”, “are there arguments among astronauts?” and “are you going to celebrate your birthday with cake, candles and presents?”. That’s how 60 young Swiss will talk to Thomas Pesquet, the French astronaut currently on-board the International Space Station for a 6-month mission.

This very special phone call will connect the ISS with around 60 students and teachers from two Swiss states (Sion and Vaud): it is offered by the ARISS program and organised by the Swiss Space Center at EPFL where I work.

Beside letting their voices be heard in space, kids will also learn about space in a few fun activities, such as: represent lunar phases with Oreo biscuits, reproduce the proportions of the Solar System by means of a toilet-paper meter and decide their menu for their trip to Mars.


The questions I reported in the opening are my favorite ones because of their innocence but there are many more curiosities the kids would like to know: I report them in the following with their author and the word “Over” that kids will have to remember to pronounce in order to hand over the communication to Thomas.

1 Léane: What time is it right now on the ISS? Over
2 Aasha: Will you celebrate your birthday with candles, cake and gifts? Over
3 Timea: Could you please describe us what you can see apart the Earth and the Sun? Over
4 Valentina: What are the funniest things you can do without gravity? Over
5 Ilhan: What do you do in your spare time? Over
6 Naya: What is the type of food that you don’t enjoy eating in space? Over
7 Elina: What were your favorite school subjects? Over
8 Ermin Do you miss your mum? Over
9 Selma: Have you been able to observe the effects of pollution on our planet? Over
10 Aya: Have you ever experienced frightening noises on both the Soyuz and the ISS? Over

11 Dana: What was your motivation to go to space? Over
12 Lauryne: Among how many candidates were you chosen and why? Over
13 Vincent: During your training, what was the most difficult task to accomplish? Over
14 Pauline: What experiments are you conducting? Over
15 Nathan: What effects does weightlessness have on your body? Over
16 Robin: Does sleeping feel different on the ISS? Over
17 Alice: What do you do if there’s a medical emergency onboard? Over
18 Nathan: Are there arguments among astronauts? Over
19 Noa: What do you miss the most of life on Earth? Over
20 Johan: What do you fear the most about your stay in space? Over

21 Leandra: Does time have the same duration on the ISS as it has on Earth? Over
22 Tarik: What is your favourite book? Over
23 Esrom: How do your colleagues and you do to have enough food and drink?  Over
24 Hayden: What is the purpose of the big rod on the top of the space rocket?  Over
25 Nolhan: From the ISS, can you see if there are still many glaciers and much snow left on the Alps? Over

And you, what would you ask? Over

Nightmare on Meyrin Street

’tis gone.
What seemed to hold the promise of a revolution in physics has fizzled out. Disappeared into oblivion. Is there really nothing more than the Higgs for the LHC to discover? Will the experiment just wander in an energy desert for the rest of its life? It is the most feared scenario physicists could have thought of before switching on the machine at CERN: a true nightmare. What now? Someone is probably hoping this nightmare will let us save money on curiosities that only experts care about and are of no public good for the majority. So wrong!

I have friends who work in theoretical particle physics: they are passionate, capable scientists and I’ve always wished the results found at LHC would help them land the permanent position they deserve to keep doing what they’re best at. Now that everyone in the field is back to square one, my friends are among the best positioned to start a new conversation with Nature through the screen of a blackboard: they are still professionally young enough to be as audaciously bold as the situation requires. So far, in fact, the community of theoreticians has mostly played by decade-old rules: no wonder we’re stuck. It is then a great opportunity to make tabula rasa and be daring. I’m confident the revolutionary men and women that’ll get us out of this morass are already born: hopefully they’re already at work and they are collaborating with each other to enjoy the benefits of complementarity.

However, things could turn out bad: the work toward a new description of Nature might take more time than my friends have to secure a job. As numerous as they can be, and even if they may come from your own country, I don’t think the destiny looming on them will move you. However, in such a case, a catastrophe will be pending above us all.

While it may look like CERN hunts for Pokemon-like entities in reality it does much more: it creates the basis for our future wellbeing. The past week, together with the sad announcement of the aborted physics revolution, CERN celebrated the 25th anniversary of the World Wide Web. It was invented there and you use it to read this piece or the news, to book the flight to go on holidays, to buy shoes and do many more things that are now given for granted in our everyday life.

CERN also has a medical research unit, where particle physics know-how from theory and experiments is put to service for health applications such as treating cancers. Moreover, for its computing needs CERN has been instrumental in the development of Grid computing, which

“… offers a way to solve Grand Challenge problems such as protein folding, financial modeling, earthquake simulation, and climate/weather modeling. Grids offer a way of using the information technology resources optimally inside an organization. They also provide a means for offering information technology as a utility for commercial and noncommercial clients, with those clients paying only for what they use, as with electricity or water.”

There is much more that CERN does for us all but I’m confident the overview I’ve given you can already let you share my concern that if we stop doing research in particle physics we stop creating needs that only this type of research can create, while their satisfaction provides the most fertile conditions for our future wellbeing and prosperity.

Before concluding, it is worth mentioning that the non-discovery of a new particle does not mean CERN should close shop just yet. In fact, knowing that the particle is not there is already a precious piece of information: we could not know beforehand, so disposing of a new piece of (non-)evidence is very useful, though painful.

At the same conference where the sad non-discovery announcement has been made a flood of other new results has been shared with the public by CERN. They still have some twenty years of activity in front of them to let the LHC machine continue its tremendously accurate and reliable work. This persistence is needed to allow new rare phenomena to show up in a significant way. Therefore, we can be “disappointed but not discouraged” as a physicist says at the end of a BBC Horizon documentary that just aired.

Last but not least, a note is in order about the title: Meyrin Street is CERN’s address for the public.

New physics, is that you?

Mysterious hints of long-awaited physics beyond the Standard Model seem to have emerged at CERN’s Large Hadron Collider

The collaborations behind ATLAS and CMS, the two general-purpose experiments at CERN’s Large Hadron Collider, have just published their latest reports. Their new data show a suspicious bump, similar to the one that gave away the existence of the Higgs boson: a detour in an otherwise smooth trajectory across the energy region explored by means of particle collisions. The reason why the new results could either hold great potential or have physicists endure a longer nerve-wracking wait has to do with how searching for the unknown works.

The Large Hadron Collider at CERN offers one the most favorable views of the Universe. Its behemoth experiments collide particles like bumper cars: in the particle dodgem debris are carefully scrutinized to reveal secrets about the interiors of the clashing entities and new types of particles can materialize into existence by converting the energy made available by the collision. Millions of particles are smashed into each other millions of times per second in order for the little sparse hints of every strike to accumulate into relevant information about the microscopic world.

Artist's rendition of a high-energy collision inside a particle detector (Image: CERN)

Artist’s rendition of a high-energy collision inside a particle detector (Image: CERN)

An everyday life equivalent of this would be tossing millions of coins millions of times and counting how many heads or tails you get. Both heads and tails being equally probable you should find that each occurs roughly 50% of the times. That’s in theory. In practice, if you throw a coin 10 times you can get heads 7 times in a row: how’s that possible?

It could be that your coin is rigged: knowing for sure this is not the case is what scientists call characterizing the experimental setup. Maybe your coin is responding to its surroundings in some unexpected way; before you can claim to have a magic coin you have to make sure you understand your environment and how this might interfere with your experiment. It could also be that, while you think you’re just throwing a standard coin, the one you got is no ordinary coin: it’s a completely new one that behaves in an unconventional way with respect to the others you have thrown in the past. More prosaically, it is possible that you did not conduct your experiment enough times to make any statistically significant claim, as scientists would say. When you toss a standard coin your outcomes will approach the 50-50% separation as you increase the number of tosses.

Counting occurrences and comparing results with expectations also characterized the hunt for the Higgs boson, when ATLAS and CMS were like Columbus’ caravels on their course to the Indies: they had to navigate an energy stretch delimited, though loosely, by previously available maps of the microscopic world; their promised land was the particle associated with the Brout-Englert-Higgs mechanism. We all know how the story went: Columbus found America instead, while the Higgs boson was indeed discovered and the duo Higgs-Englert was awarded the Nobel Prize for physics, absent the late Brout.


Professor Englert and Professor Higgs speaking at the Higgs seminar announcement at CERN in July 2012 (Image: CERN)

Since then CERN has been making history, though in a peculiar sense. Its LHC works in fact as a time machine, by concentrating energy to values that characterized the Universe only immediately after the Big Bang. Now we can rewind a movie no one has ever watched before and directly witness the story unfold as if it were the first time. We have some expectations about the movie but this time around the situation is trickier than in the Higgs-Columbus days: we have left America. The map we could use until then, the so-called Standard Model, is not adequate anymore.

Every model is a description of Nature that is optimized for a specific set of its features and the Standard Model makes no exception: it is very accurate in its domain but cannot explain 95% of the Universe. These dark sectors are like very dim, unexplored rooms in a castle: to build a detailed map of these rooms we need to probe them, to understand their architecture and the variety of their furniture we need landmarks that inform our bearings.

ATLAS and CMS scientists have just finished analyzing information that seem to suggest a new landmark could exist, what exactly is still up for debate: it could be as familiar as a cousin of the Higgs boson or as novel as a manifestation of extra dimensions. This uncertainty represents science in the making and is very fruitful for researchers because it compels them to go through a checklist that resembles the one about the coin toss: are we dealing with a completely new coin? Or will new tosses wash away the seven-heads-in-a-row occurrence?

Only time and more data will tell if we have finally found new physics beyond the Standard Model: after all we have just started watching the movie about the history of the Universe.

Another Earth

I just had breakfast and it made me sick. I had a yoghurt and some cherries. The bones of the cherries now sit in a bowl, together with those of the apricots I had for dinner yesterday. Later, when I go out for a walk by the lake, I’ll let them slide from the bowl down in the compost bin, to join the green rests of the households around mine.

The yoghurt pot sits in the trash bag: when it joins the trash bags of the other people living in my condo it’ll either be burned or take a ride to a landfill and be dumped there, not so many kilometers from where I live but enough to be out of sight and out of mind.

My life produces waste that either chokes the atmosphere or fills the interiors of my planet: I behave as if it will never come back to me. I guess that’s the rule of the game: if you don’t see it with your eyes, it doesn’t exists, ergo it’s not a problem.

This is what makes me sick. Every time I unpack food there’s something to be thrown “away”. I feel it like a shadow that persistently walks behind me: at every toss it grows, so I should notice better, instead I let it grow larger and larger … sooner or later it’ll cover a sizable part of the planet where I live, the most beautiful planet we know of, Earth.

A couple weeks ago NASA shared a new catalog of planets discovered beyond our cosmic backyard. Earlier on, they told us about the discovery of a planet that could be our big brother or cousin: called Kepler 452-b, it’s just a bit older and larger than Earth but otherwise very similar. One of the tweets I reposted about that announcement said:

“Hopefully aliens on Kepler 452-b have telescopes that have just discovered Earth, and are very excited to have found Kepler 452-b’s twin!

If these aliens exist, I wonder how they live, if they have established a more considerate way to prosper on their home planet, taking responsibility for their actions, making choices for the future of their environment, where their descendants will live after these decisions have been taken on their behalf.

I hope these beings are not oblivious to these implications just because they are not the ones who’ll have to deal with them. I wonder if they are living as hypnotized as we are, formatted to think that what we have been given as habitudes are the right ones just because everyone else does like this and it’s always been this way … or because it’s too annoying to think so deep: everyday life already has its problems, right?


Make sure you visit the other options at the Exoplanet Travel Bureau.

That’s what my mom and sister tell me, when I suggest them to consider behaving differently toward our planet. I try to remind them that it’s not just their planet, it’s everyone’s! it’s where our little niece will grow up: what will we answer them when they ask: “you knew you were screwing my world up, why didn’t you do anything? how could you be so lazy and selfish?”

I think my mom and sister frame the discourse about the environment as feeling obliged to comply with some impersonal diktat. I, on the contrary, feel empowered by what each of us can do to live in a better equilibrium with the world that supports us and feeds us, as it’s done with those who came before us; how would we feel if they had left us what we are preparing for our sons and daughters? what would we think of them?

A friend recently reminded me that evolution is morally blind and that humans do not thrive on Earth because they are the best possible people: while from a scientific point of view I know this is true, I still dream of humans inhabiting Earth for deeper reasons than natural selection, medicine and technology, like this young guy is doing


What can I do?

I’ve started washing the plastic yoghurt pots to recycle them.

I try to take fewer and shorter hot showers.

I mean to go back using a fabric tissue instead of paper ones.

I want to buy a metallic bottle to carry water around.

What more can you suggest me? 

Reflections on a black mirror


If I ever write a novel “Reflections on a black mirror” would be a tempting title. In the meantime it is the typical title of an entry in the “gr-qc” bulletin, which comes out Monday to Friday, holidays permitting, and lets you find out what’s up in the world of “General Relativity and Quantum Cosmology” research.

You would think it is too much of an arcane world to be interesting to the uninitiated and you wouldn’t be wrong. However this research is done by men and women that live in the same world as we do. It just so happens then that sometimes researchers express esoteric concepts by appealing to common language and expressions from the pop culture.  Here you are a few peculiar entries in this sense for your own surprise and amusement: I’d like them to serve as an entry door for you to this branch of physics. Pick the most tempting title and go read the relative abstract; then feel free to ask me to expand on your favorite one.

To conclude, I’d like to show you an example that best encapsulates the take-away message from this post: science is an open business, where even gravity is still up for a deeper explanation! The example I chose is among the plainest I could find. It relates on the nature of gravity, and uses many topical expressions of the research world, such as: perspective, concordance, implications, evidence, approach, attempts, problem, solution, (mis)understanding, alternative. This is how the research community let the Universe speak through gravitational waves, this is how humanity will get to the conquests of tomorrow, both scientific and technological: with such brainstorming as the one daily hosted on the “gr-qc” bulletin.

Who you gonna call? Researchers!

When a new virus appears … Who you gonna call? Researchers!

When Einstein wants to be vindicated … Who you gonna call? Researchers!

When climate seems to go crazy … Who you gonna call? Researchers!

When a new planet seems to be lurking in the Solar System … Who you gonna call? Researchers!

When you need robots to enter nuclear plants … Who you gonna call? Researchers!

When antibiotics are not effective anymore … Who you gonna call? Researchers!

When you want to know how red the Red Planet is … Who you gonna call? Researchers!

When you need a machine that cracks numbers quicker than you can … Who you gonna call? Researchers!

When you want to optimize traffic … Who you gonna call? Researchers!

When you need safer cars … Who you gonna call? Researchers!

When you want energy for the future … Who you gonna call? Researchers!

When you need clean water for the poor … Who you gonna call? Researchers!

When you want to reinforce the bones of the elderly … Who you gonna call? Researchers!

When you need to communicate faster … Who you gonna call? Researchers!

When you want light rays to scan your body … Who you gonna call? Researchers!

When you need particle beams to cure your tumors … Who you gonna call? Researchers!



Review paper on the physics of proton therapy:

The Atlantic highlights some cool health-based spinoffs:

High Speed Camera Used In Space Adapted To Scan Skin Cells

wi-fi and astronomy:

Eye-tracking technology developed for ISS research now being used in laser eye surgery

This is how the camera in your phone came to be.  The invention and early history of the CCD

To teachers

A few days separate us from The Global Teacher Prize 2016 Winner Announcement and I’ve discovered this personal endorsement from Stephen Hawking:

His words are very passionate and the account personal; these two excerpts have touched me in a particularly deep way:

“ … for each mind to achieve its full potential, it needs a spark. The spark of enquiry, excitement, and passion. Often that spark comes from a teacher. [ … ]

I wasn’t the easiest person to teach: I was slow to learn to read and my handwriting was untidy. But at the age of 14, my teacher, Dikran Tahta, showed me how to harness my energy and encouraged me to think creatively about Maths. He made me wonder, he made me curious, he opened up new worlds to me … that is what a great teacher can do. ”

To teachers!!!